MACTRA. 



Plate XX. 



Species 112. (Mus. Cuming.) 



Mactb.\ jEgyptiaca. Mact. tedd transversim ohloiiga, 

 valde iuwqitilaterali, uti'inque kiante, ieiinicidd, Can- 

 dida, versus extremitates epidermide tenni induM, 

 dense radiatim, irregiilariter acute Uratd, lirarmii iii- 

 terstitiis cancellato-striatis, latere antico obtuse ro- 

 tundato, postico niulto longiore, attenuato-rotundato, 

 compresso ; extremitatibus lirls panis oblliitie diver- 

 gentibm exsciilptis. 



The Egyptian Mactea. Shell transversely oblong, very 

 inequilateral, gaping at each end, rather thin, white, 

 covered towards the extremities with a thin epider- 

 mis, densely radiately irregularly sharply ridged, in- 

 terstices between the ridges cancellately striated, an- 

 terior side obtusely rounded, posterior much the 

 louger, attenuately rounded and compressed ; ex- 

 tremities sculptured with line obliquely diverging 

 ridges. 



Chemnitz, Conch. Cab. vol. ii. p. 318. pi. 200. f. 1955-6. 

 Lutraria jEgyptlaca, Hanley. 



Hab. Ceylon ; E. L. Layard. 



This species, which M. Deshayes ascribes to the M. 

 Mgyptiaca of Chemnitz, should properly have another name. 

 The specimen here figured is from Ceylon. 



Species 113. (Mus. Cuming.) 



Mactra Solandri. Mact. testa transversim ocatd, sitb- 

 cuneiformi, inaquilaterali,' tenui, Candida, irregiilari- 

 ter radiatim acute Uratd, liris posticis distantioribus 

 et acute elevatis, latere antico rottmdato, postico lon- 

 giore, kiante ; umbonibus subappressis. 



Solander's Mactra. Shell transversely ovate, some- 

 what wedge-shaped, inequilateral, thin, white, irre- 

 gularly radiately sharply ridged, posterior ridges 

 more distant, and sharply raised, antei'ior side 

 rounded, posterior longer, gaping ; umboes rather 

 appressed. 



Spisula Solandri, Gray, Ann. and Mag. Nat. Hist. 1837. 

 p. 373. 



Hab. Moluccas. 



A thin white shell, gaping at the posterior end, with a 

 somewhat Pelricola-Wke aspect ; tlie posterior ridges are 

 peculiar in being more distant and sharply raised. 



Species 114. (Mus. Cuming.) 



Mactea Califoenica. Mact. testd transversim oblongd, 

 incequilaterali, lavigatd vel subrude concentrice stri- 

 atd, calcareo-alhd, epidermide flavidd indutd, laterali- 

 biis subaqualiter rotimdatis, postico longiore ; umbo- 

 nibus minutis, approximatis. 



The Californian Mactra. Shell transversely oblong, 

 inequilateral, smooth, or rudely concentrically stri- 

 ated, chalk-white, covered with a yellow epidermis, 

 sides nearly equally rounded, posterior side the 

 longer ; umboes very small, close. 



Deshayes, Pro. Zool. Soc. 1854. 



Ilab. California. 



This species is not distinguished by any peculiarity of 

 form or sculpture, and has very much the appearsmce of a 

 small Ml/a. 



Species 115. (Mus. Cuming.) 



Mactra rugosa. Mact. testd transverse ovatd, gibbosd, 

 utrinque Juante, valde ina:quiluterali,fuscescente-albd, 

 calcared, radiatim irregiilariter Uratd, ad extremi- 

 tates Icevigatd, latere antico brevissimo, rotundato, 

 postico oblongo, producto ; mnbonibns parvis, appressis, 

 approximatis. 



The rough Mactra. Shell transversely ovate, gibbous, 

 gaping at each end, veiy inequilateral, brownish- 

 white, chalky, radiately irregidarly ridged, smooth at 

 the extremities, anterior side very short, rounded, 

 posterior oblong, produced ; umboes small, appressed, 

 close. 



Chemnitz, Couch. Cab. vol. vi. p. 336. pi. 34. f. 336. 

 Lutraria rugosa, Lamarck. 

 Spisula rugosa. Gray. 



Hab. Faro, Portugal. 



A large rough species, very irregularly radiately ridged, 

 except at the extremities, which are smooth. 



Species 116. (Mus. Cuming.) 



Mactra Thracioides. Mact. testd ovatd, antice gib- 

 bosd, utrinque kiante, inaquilaterali, tenui, opaco- 

 albd, concentrice dense Jibroso-striatd, oblique undula- 

 tim corrugato-plicatd, latere antico rotundato, postico 



May, 1854. 



